setTimeout是指过多久执行，只执行一次
setInterval是指每过多久执行一次
clearTimeout是关闭setTimeout定时器
clearInterval是关闭setInterval定时器，不让它一直执行
<html>
<head>
<title></title>
</head>
<style>
</style>
<script>
window.onload=function(){
var aButton=document.getElementsByTagName("input")
var timer=""
var inter=""
aButton[0].onclick=function(){
debugger
inter=setInterval(function(){
alert("1")
},1000)
}
aButton[1].onclick=function(){
clearInterval(inter)
}
aButton[2].onclick=function(){
timer=setTimeout(function(){
alert("1")
},1000)
}
aButton[3].onclick=function(){
clearTimeout(timer)
}
}
</script>
<body>
<input type="button" value="开启Interval" />
<input type="button" value="关启Interval"/>
<input type="button" value="开启timeout"/>
<input type="button" value="关启timeout"//>
</body>
</html>
JS中定时器setTimeout,setInterval,clearTimeout,clearInterval用法
原文：https://www.cnblogs.com/superCwen/p/9807572.html